Congenital Cardiovascular Disorders: Clinical Presentation and Management

Atrial Septal Defect (ASD)

ASD involves a hole in the atrial septum. Patients are often asymptomatic in childhood but may fatigue easily. Physical findings include a widely split, fixed $S_2$ and a systolic murmur at the pulmonic area. While small defects may close spontaneously, larger ones require intervention to prevent right ventricular enlargement.

Ventricular Septal Defect (VSD)

VSD is the most common congenital heart defect.

• Small VSDs: Present with a harsh, high-pitched holosystolic murmur at the left lower sternal border (LLSB).
• Large VSDs: Often present with signs of Congestive Heart Failure (CHF).

Warning: Signs of CHF

• Infants: Tachypnea, tachycardia, poor feeding, poor weight gain, diaphoresis, and hepatomegaly.
• Children/Teens: Orthopnea, dyspnea with exertion, and peripheral edema.

Atrioventricular (AV) Canal Defect

This defect involves the central cardiac structures and is highly associated with Down syndrome. Complete defects often require surgical repair before 6 months of age to prevent severe CHF.

Patent Ductus Arteriosus (PDA)

PDA is the failure of the ductus arteriosus to close after birth. In preterm infants, closure can be induced using Indomethacin or ibuprofen.

Cyanotic Defects (Right-to-Left Shunts)

Cyanotic defects involve deoxygenated blood bypassing the lungs and entering the systemic circulation, leading to low oxygen saturation.

Transposition of the Great Arteries (TGA)

In TGA, the great arteries are switched, resulting in poor mixing of oxygenated and deoxygenated blood. This is a medical emergency requiring immediate Prostaglandin $E_1$ to maintain ductal patency, followed by arterial switch surgery.

Tetralogy of Fallot (TOF)

TOF is characterized by four distinct defects: pulmonary stenosis, right ventricular hypertrophy, overriding aorta, and a VSD.

• Clinical Hallmark: "TET spells" (hypercyanotic episodes) often triggered by crying or feeding.
• Emergency Management: Place the infant in the knee-chest position, administer oxygen, and provide morphine sulfate.
• Imaging: Chest X-ray typically shows a "boot-shaped heart".

Hypoplastic Left Heart Syndrome (HLHS) and Tricuspid Atresia

These are "single ventricle" defects where the left side of the heart is underdeveloped. Survival depends on maintaining a patent ductus arteriosus via Prostaglandin $E_1$. These patients often require complex palliative surgeries or heart transplantation.

Obstructive Lesions

Aortic Stenosis (AS)

AS involves narrowing of the aortic valve, often due to a bicuspid valve. It presents with a harsh systolic crescendo-decrescendo murmur at the upper right sternal border and a narrow pulse pressure.

• Management: Depends on severity. Newborns may undergo balloon valvuloplasty.
• Activity Guidelines:
  • Mild: Allowed to participate in sports with annual exams.
  • Moderate: Low-intensity sports only.
  • Severe: Avoid sports entirely.

Coarctation of the Aorta (COA)

COA is a narrowing of the aorta. The classic physical finding is upper extremity hypertension paired with lower extremity hypotension and weak distal pulses. In critical neonates, Prostaglandin $E_1$ is used to maintain ductal patency until surgical intervention.

Long-Term Management and Prophylaxis

Patients with repaired or unrepairable congenital defects require lifelong monitoring.

• SBE Prophylaxis: Subacute Bacterial Endocarditis (SBE) prophylaxis is required for 6 months following surgical repair or if prosthetic material is used.
• Transition to Adult Care: Many patients are lost to follow-up during the transition to adulthood. It is vital to monitor for late complications such as arrhythmias, sudden death, or progressive stenosis/regurgitation.

Exam Alert: Sudden Cardiac Death (SCD) When screening athletes, always inquire about a family history of premature death (before age 50) due to heart disease, or a history of syncope during exertion.